Electromagnet and voltage divider



Feb. 1o, 1931. F. CUTTING 1,792,077

` ELECTROMAGNET AND VOLTAGE DIVIDER Filed Jan. 9. 1928 m kn l* figg-f- 4+ PowER B +AMPL. B

+ DEL B xINVENTOR DetentedFe-b. l0, 1931 .l

UNITED s'rf'ras PATENT OFFICE.

FULTON CUTTING, OF NEW YORK, N. Y.

ELECTROMAGNET AND VOLTAGE DIVIDEB Application filed January 9,' Y1928. Serial No. 245,519.

My invention relates particularly to imcurrent or rectified commercial alternating provements in radio broadcast receivers. current.

One object of my invention is. to simplify The winding is so proportioned as to the filtration of the anode current source. give the proper field with whatever maximum A Another object is toy provide a more `efficient voltage is chosen for the anode source. The 55 loud speaking telephone without requiring anode voltage for the last audio frequency any appreciable amount of additional power stage 5 is tapped off from the winding 10 at for the operation of the receiver, thereby inthe point 14 and the condenser 15 provides creasing its overall sensitivity. the alternating current return. The anode Another object is to cheapen the construcvoltage for the audio frequency stage 4 and 30 tion of the anode current filter of a radio rethe radio frequency stages 1 and 2 may be ceiver and at the same time increase the powtapped off from the polnt 16 and4 the coner and sensitivity of its associated loud speakdenser 17 provides the alternating current re-V ing telephone. I turn for these three stages. The detector Another object is to supply asimple and reanode voltage may be tapped off from the e5 liable source of grid biasingvoltage. point 18 and the alternating current return Referring to the drawings, Fig. 1 shows a provided for by the condenser 19. Atypical receiver employin two stages of It will be seen that by proper arrangement tuned radio frequency amp ification, a detecof taps the desired anode voltage may be ap- 2o tor and two stages of transformer coupled plied to anytube or group of tubes. Thefield 70 audio frequency amplification,` although it winding constitutes the inductive part of a should be understood that I do not care to typical inductance-capacity filter. It is the limit my invention tol use with any particuusual practice to run the radio frequency lar form of radio receiver. y tubes on a moderate anode voltage, the detec- Fig. 2 shows the field Winding of an -elec tor at a low anode voltage and the last audio 75 tro-dynamic speaker similar. to that illusfrequency or output tube at a high voltage. trated as part of Fig. 1 but with an additional An alternating current component in the antap to provide negative grid bias or C voltode voltage is most disastrous in the detector a e. tube, less so in the first audio frequency am- In Fig. 1, the rst and second stages of radio plifier and still less so in the output tube, the so frequency amplification are shown at 1 and 2 reason, of course, being that any alternating respectively, the detector and its associated current component in the detector tube is amcircuits at 3, the first stage of audio frepliiied twice before being reproduced in the quency amplification at4and he second stage loud speaking telephone, and any fluctua at 5, this latter stage prefera ly em loying a tions in the anode voltage in the first audio 85 power tube at 6 and a grid biasing attery 7. frequency amplifier is amplified'once before A loud speaking telephone of the electrobeing reproduced. dynamic type is dlagrammatically indicated It will be seen that according to my inat 8. 9 indicates the field core and 10 the field Vvention the amount of filter inductance is winding.` This winding for the reasons leregreatest for the detector, least for the output 90 after set forth should have a much greater tube, and a value of inductance between number 0f tllI'IlS than the conventional type -these two points may be chosen for the first design for operation at cathode heating voltaudio frequency amplifier, which, as above ages, v11 represents the moving coil, 12 a diaset forth is the proper relation. Thus, it

4i phragm of any suitable type. will be seen that the appropriate voltages 9.1" 1" A condenser 13 of suitable value may be land the appropriate amount of filter in-v placed across the input leads of the field Windductances may be said to go hand in h ing, which, as indicated in the drawing, are in my invention. connected to the anode source +B, -B Fig. 2 is a modification of the field windwhich may preferably be commercialr direct ing shown'at 10 in Fig. 1 so arranged as to 100 provide not only various voltages but also to provide grid biasing or C volta Thecore `9 carries the 'lield windin 10' having the taps 14,216', 1,8', 20 an 21.

Filter condensers, such as, 15, 17, 19, Fig. 1, may be provided. The tap 14 may provideanode voltage for theoutput tube or power amplifier. The tap 16 may sug.-

1y a somewhat lower voltage to the amp er tubes, and the tap 18 a still lower volt- .age to the detector anode supply.

The point circuit at a suitable point and the voltage dro between this oint and the point 21 1s us to supply gri bias or C voltage to such tubes as desired. x

By means of m invention a very much moreA efficient an owerful loud speaker may bel provided wit very little addition to the cost of the anode supply filter alone.

It should be understood that I do not wish to limit vm self to the specific form shown in the specification, only in so far as I am limited by such claims as may be allowed. Y

1. In combination iwith a radio receiver having vacuum tubes and an anode power source, an electro-dynamic loud speaking telephone having a field winding, said windanode source, said ta s eing connected to the anodes of the various tubes.

2. In combination, a radio receiver having valves each with at least three electrodes, an anode wer source, and a loud speaker having a eld winding having taps, and bein connected to said anode power source sai taps being connected to the anodes of various of said valves, said ta s being so spaced apart as' to supply the esired voltages to said various valves and said winding acting as a filter inductance for said anode power source.

3. A radio receivin system having electronic relays arrange for radio frequency amplification, detection, and audio frequency amplification-and an electrodynamic speaker having coil windings tapped appropriately to serve as a voltage divider for the plate anode circuits of saidvarious relays.

4. In combination, a powerv supply, an electro-dynamic loud speaker with a field magnetic of connection between sud the anode su ly source for energizing the field) of said speakerz of connection between the taps of said-windings andthe receiver so that the windings function as a filter inductor for the receiver, and at the same time deliver appropriate voltages to the various anode circuits of said receiver.

r FULTON CUTTING.

20 is connected to the filament ing having taps and bein connected to said ,I

winding having taps, substantially all of said winding beingconnected across said p ower supply, one part of said winding functioning asa voltage divider to supply anode voltages of differingmagnitudes to various of the vacuum tubes of a radio receiver, another part of said winding being used to supply grid biasin voltage to certain of said vacuum tubes, sai windin acting as a filter inductor for said suppli voltages.

5. AA radio receiver having vacuum tubes 65 an anode supply source for said tubes, a lou ioo iis 

